# "|X|=1480 LBS, |Y| = 1240 LBS, they act on a angle of 30 degrees to each other..."

• Oct 29th 2009, 12:55 PM
Wolvenmoon
Solved!....they act on a angle of 30 degrees to each other..."
Attached is an image with my questions right on where I stop understanding this problem.

"Force X has a magnitude of 1480 pounds, and force Y has a magnitude of 1240 pounds. They act on a single point at an angle of 30 degrees to each other. Find the magnitude of the equilibrant and the angle between the equilibrant and the 1480 pound force."

So, to my understanding if we have vector "V" its equilibrant is "-V" and has the same magnitude as "V" but heads off in the opposite direction. This means that finding |V| gives |-V| ( Knew they weren't just using the absolute value signs for nothing! )

Using the parallelogram rule and labeling it, I end up with what appears to be angle A = 30 degrees, angle B = 150 degrees, and angle C = 30 degrees ( as adjacent sides in a parallelogram add to be 180 ), then it's a quick application of hte law of cosines on triangle ABC and I have my magnitude.

...and typing this out I'm not coming to a eureka moment as I sometimes do when I have a question and start to ask. I can get the magnitude, and I can mechanically get the angle they're talking about, but it's through memorization and not understanding. What is angle CAB?

I'm off to file a support ticket with coursecompass as the video tutorial was on the previous section, then the guy started talking REALLY FAST for two parts of this section.

Solution for me: "Angle CAB" is a fancy way of saying "Angle A", which is NOT the same as the angle the two forces meet and act on.
• Oct 30th 2009, 01:37 AM
james_bond
I haven't read the whole thing but the absolute value signs mean the length of a vector...
• Oct 30th 2009, 11:57 AM
Wolvenmoon
I was referring to the length of a vector ( at least from what I know so far ) being distance, magnitude itself doesn't have direction, so re-using the pipe signs for magnitude of a vector isn't confusing.

Quote:

Originally Posted by Wolvenmoon
...and typing this out I'm not coming to a eureka moment as I sometimes do when I have a question and start to ask. I can get the magnitude, and I can mechanically get the angle they're talking about, but it's through memorization and not understanding. What is angle CAB?

• Oct 30th 2009, 03:42 PM
Wolvenmoon
Figured it out.